Antigen Test may allow Covid-positives entry into Goa

By Ashwin Tombat
02 August 2020 09:45 IST


The decision of the Goa government to replace RT-PCR tests at the Goa Airport with Antigen tests is baffling. It is true that Antigen testing is rapid, giving results within 20 minutes, while the RT-PCR test takes a minimum of 24 hours and, given the present backlog, produces results only after four or more days.

But Antigen tests can produce a false negative result.

In fact, the Indian Council of Medical Research (ICMR) says that those who test negative for Covid-19 by rapid antigen test should necessarily be re-tested by RT-PCR to rule out infection. On the other hand, a positive test should be considered as a true positive and does not need reconfirmation.

Why is the Goa government relying on a test for those entering the state that gives false negatives? This opens up the possibility that a person that tests “negative” at the airport and is allowed in the state without quarantine may actually be Covid positive! Isn’t the government needlessly endangering the health of residents?

It is precisely quixotic decisions like these that have brought Goa to its knees in the face of the ongoing pandemic.

On 20 April, Goa was declared Covid-free. By ramping up its health infrastructure and restricting interstate movement, Goa had managed to push back the disease, Health Minister Vishwajit Rane then told an admiring national media. It was India’s first ‘Green Zone’.

In stark contrast, Goa witnessed its highest single-day rise of 280 cases on Saturday 1 August, clearly showing that Chief Minister Pramod Sawant’s three-day state-wide weekend lockdown – from Friday 17 July to Sunday 19 July – was an abject failure. How did a state that was declared a green zone in early May fall so far so soon?

For 23 days, Goa was officially Covid-free. On 14 May, after movement of stranded persons by trains was allowed, cases started mounting. By 30 May, there were 70 confirmed cases, all from outside, and all in control.

On 1 June, two Covid-positive cases were reported in Mangor Hill, Vasco. It started with a trader who bought scrap fish and used it to make chicken feed. He was in touch with truck drivers transporting fish from outside Goa. Truck drivers’ services were considered “essential”. They were not being tested at the border. That is how the Coronavirus got its first foothold in Goa.

What followed was a botched containment at Mangor Hill. The CM refused to make all of Mangor Hill a containment zone. He refused to extend the containment zone to Vasco, even though the local MLA begged him to lock down the whole town. Then, the infection spread through workers in the nearby Verna Industrial Estate, where people from all over the state come for work; many using crowded public transport. They acted as super-spreaders, taking Covid-19 deep into Goa’s villages, and bringing the state to a point of no-return. Government action has been too little, too late…

In fact, some of the government’s actions have had the effect of actually helping the infection to spread. Take the case of teachers. Even though all educational institutions were closed and teaching, if any, was solely over the Internet, the state government insisted that school, higher secondary, college and university teachers must physically report to work.

Even after the Union Ministry of Home Affairs (MHA) directed that teachers all over the country must work from home, the state government insisted that Goa’s teachers must continue to physically report to work. Thousands of teachers had to take public transport, travel on two-wheelers or carpool to work and back each day, for no good reason. What was the logic in needlessly exposing them and their families to Covid-19 infection…?

To be fair, the Goa government also has some notable successes. As of 21 July, Goa recorded the highest testing rate per million population in the country, at 68,374. This was followed by Dadra and Nagar Haveli at 60,728, Ladakh at 56,974, the Andaman and Nicobar Islands at 46,103 and Delhi at 44,383. The lowest number of tests per million population were in Bihar (3,113), Jharkhand (5,772), Uttar Pradesh (6,363), Telangana (7,017) and West Bengal (7,191).

No country or state knows the actual number of people infected with Covid-19. All we know is the infection status of those who have been tested. This means that confirmed cases depend on how many people are actually tested. Countries and states that claim to be doing “well” but test very little may be underreporting cases and deaths. Under no circumstances can Goa be accused of this.

But let us come back to the point. Why, exactly, are antigen tests dangerous? Antigen tests seek out specific proteins only found in the virus. Most antigen tests target the 'spike protein' that studs the surface of the coronavirus.

A swab from the nose is collected for this test. It is dipped in a solution that inactivates the virus, which is then transferred onto a test strip. If the sample is positive, coloured lines show up on the paper strip in 15 to 20 minutes.

But since antigen testing doesn't amplify the virus or its genetic material (which is what the RT-PCR test does), a swab sample may have too little antigen to be detected. This could produce a false negative result. That is why the ICMR recommends that a negative Antigen test should be followed by the more accurate RT-PCR test, to confirm a true negative for Covid-19. A positive test does not need reconfirmation.

The Goa government is making money at the airport, charging Rs2,000 for an Antigen test that actually costs around Rs450. But this may be at the cost of the health of the state’s citizens. Incoming travellers that test “negative” at the airport and are allowed into Goa without quarantine, may actually be Covid-positive and spread the infection all over the state!

Disclaimer: Views expressed above are the author's own.

Blogger's Profile

Ashwin Tombat

Ashwin Tombat has been the Editor of Gomantak Times and Herald. Worked as an Associate Editor of national magazine Gentleman in Mumbai, before shifting to Goa. Loves sailing, also participates in Marathons. Has worked as an activist in students's union and trade unions in Maharashtra. Also an artist of Street Theatre during student days.

Drop a comment

Enter The Code Displayed hereRefresh Image

Related Blogs